Process of treating the surface of articles made of cured carbon.



M Isl/89546 5R UNITED STATES PATEN OFFICE.

JOSEPH L. K. SNYDER, OF CLEVELAND, OHIO, ASSIGNOB. 'TO NATIONAL CARBONCOMPANY, OF CLEVELAND, OHIO, A. CORPORATION OF NEW JERSEY.

PROGESS-OF TREATING THE SURE-ACE OF ARTICLES F CURED' CARBON.

No Drawing.

To all whom it may concern:

Be it known that I, J osnrn L. K. SNYDER, a citizen of the UnitedStates, residing at Cleveland, in the county of Cnyahoga and State ofOhio, have invented a certain new and useful Improvement in Processes ofTreating the Surface of Articles Made of Cured Carbon, of which thefollowing is a full, clear, and exact description.

Y Articles made from carbon and cured by heat have a very hard, smooth,dense external' shell or skin. There are many uses for which said carbonarticles are adapted, which requirethe application of some surfacecoating. It is very difficult, however, to cause such coating to adheresuitably to thei smooth, dense external skin of the artic e.

This invention relates to a process for overcoming this difiiculty, andconsists in making the skin more porous by dipping in 2. suitable liquidagent, heating the article to drive out the volatile part of said'agent,

and then applying the coating. I have found that either an acid such assulfuric acid, or an alkali, came soda solution, will make theskinnfithcn ilfi lql29rous when used as theli'qnidggent in the processdesgribed. I ani unabl e to advance a theory Specification of LettersPatent.

Patented Apr. 11, 1916.

Application filed September 23, 1910. Serial No. 583,446.

for the phenomena, but the fact remains that carbon articles are madeporous by the treatment. After having opened the pores of the articlethecoating that is to be applied to the carbon article adheres tenaciously,as the same enters the minute interstices in the skin.

A preferred way for carrying out the process is to dip the carbonarticle in the solution for about 30 seconds, removing it therefrom, andc yeringi.-J Zithih0t-9 5e to drive off the volatile part of the liquid,though the heating obviously may be carried on in other ways.

Having described my invention, what I claim 1s 1 I 1. The process ofcoating carbon artlcles,

which consists in opening the pores in the skin and then applying thecoating.

2'. The process of coating carbon articles, which consists in dipping the article in a liquid such'as anacid or an alkali, heating the articleand then applying the coating.

In testimony whereof, I hereunto affix my signature in JOSEPH L. K.SNYDER. Witnesses: E. L. Tmmsron, H. R. SULLIVAN.

copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patent,

' walhingtoml). O. r

the presence of two witnesses.

3 as c.

